The walls before Ed were tall, but not tall enough. They fell short of the wall in Sanctuary and they fell specially short of stopping obstinate intruders. To be fair, most walls could fall rather easily if there was no one to defend them.
Still, gazing up at the top of the wall invoked some sort of… melancholy. The cracked and unmaintained walls were likely the source of this unknown sadness.
Giving into this melancholy, Ed turned off his sixth sense for a moment. He wanted to take in the environment past the walls as it was, without any obstructions whatsoever. Though the chances of him finding anything with life in there was slim anyway.
As there were many cracks on the wall, it was pretty easy to climb. The edge at the top extruded making it a bit uncomfortable to get up but Ed's slim limbs did not lack strength.
